Fluorinated ethers and derivatives



United States Patent a co oration of Delaware No I J raWing. Filed Feb. 2, 1959, Ser. No. 790,334 11 Claims. (Cl. 8-116.2)

This invention relates to halomethylethers and more particularly to certain new N-perfiuoroalkylsulfonamidoalkyl halomethylethers and quaternized derivatives thereof, and to a process for rendering textiles soil-resistant as well as oil and water repellent.

The novel halomethylethers of the invention conta n a halogen atom attached to a perfiuoroalkylsulfonamidoalkyl group through a labile oxymethylene radical. These halomethylethers are found to react w1th tertiary organic bases to form quaternary ammonium derivatives. When the perfluoroalkyl group contains from about 6 to about 12 fully fluorinated carbon atoms, it has been found that these compounds can be employed as textile finishes, and particularly to treat cellulosic materials such as cotton to produce a chemically bonded water and 011 repellent finish material for such cellulosic materials.

While it has heretofore been found possible to produce valuable and useful soil resistance, and oil and water repellency, in wool and certain synthetic fibers, it has been difficult to produce lasting effects on the cellulosic fibers. The finishes heretofore developed for this purpose, such as those which employ amide-quaternary amines as described in US. Patent 2,303,191, have been relatively easily removed, often by a single launderingoperation. They have also required the deposit of relatively large amounts of the treating agent on the fibers, as compared with the compositions of the present invention.

It is an object of this invention to provide quaternizable halomethyl ethers possessing fluorocarbon tails.

Another object of this invention is to provide agents by means of which cellulosic materials and particularly cotton fibers can be rendered lastingly oil and water repellent. A further object of this invention is to provide oil and water repellent cellulosic materials such as cotton cloth. Still another object of the invention is to provide a process for rendering cellulosic materials soilresistant. Other objects will become apparent hereinafter.

In accordance with the above and other objects of this invention certain novel halomethyl ethers have been discovered which are useful for the production of quaternary salts containing a perfiuorocarbon tail. These compounds can be represented by the formula:

wherein R,- is a perfluoroalkyl group containing 4 to 12 carbon atoms (providing the perfluorocarbon tail which has certain useful characteristics as set forth in US. Patent 2,803,656, R is an alkylene bridging group containing l to 12 carbon atoms, R is hydrogen or an alkyl group containing 1 to 6 carbon atoms and X is chlorine or bromine.

It has been found that these novel halomethyl ethers readily react with tertiary organic bases to produce novel surface-active quaternary salts represented by the formula:

wherein Q represents a nitrogenous organic residue having the free valence attached to the nitrogen atom and three other valences attached to at least two carbon atoms, and bearing a positive charge.

It has further been found that the quaternary salt derivatives of the compounds of the invention can be applied to woven and non-woven fabrics as more fully described hereinafter to provide oil and water repellency with improved resistance to laundering. For this purpose those quaternary compounds represented by the formula:

tion are prepared by reaction of perfluoroalkanesulfonamidoalkanols of the general formula:

wherein R R and R have the significance set forth above, and which are described and claimed in US. Patent No. 2,803,656, with formaldehyde and anhydrous hydrogen chloride or anhydrous hydrogen bromide. The resulting perfiuoroalkanesulfonamidoalkyl halomethyl ethers are waxy solids having softening points of from about 25 to about C.; that is, they vary in consistency from that of hard butter to that of beeswax or carnauba wax. When sufiiciently pure they are white, but as commonly obtained they are slightly yellowish in color. This does not affect their utility for quaternization, and special purification prior to quaternization is not necessary.

The process for preparation of the halomethyl ethers is conveniently carried out by passing the selected anhydrous hydrogen halide in gaseous form into a solution of the alkanol and paraformaldehyde in an inert solvent such as toluene, benzene and the like, until there is substantially no further absorption of the hydrogen halide.

As the reaction is not strongly exothermic, no temperature control is required, although heating from about 25 C. to 100 C. (depending to an extent on the boiling point of the solvent used) may be resorted to to insure completion of the reaction. The halomethyl ethers are then readily isolated by evaporation of the solvent and are obtained as residues which can be purified if desired as by fractional distillation under reduced pressure, recrystallization or the like, but which are conveniently employed without further purification, e.g. for quaternization. Although amide linkages are sometimes cleaved by acidic reagents, this does not appear to occur during the preparation of the compounds of this invention even though the strongly hydrogen halides are employed.

Quaternization is conveniently eifected by dissolving the selected halomethyl compound in anhydrous ether or other solvert (such as toluene, benzene or dioxane) in which the quaternary salt is insoluble and adding the desired tertiary organic base, while heating at a temperature in the range of about 25 C. to 100 C. For this purpose tertiary amines, including trialkyl amines such as trimethylamine, tributylamine and tridodecylamine; alkarylamines such as dimethylaniline; and heterocyclic amines such as pyridine, picoline, lutidine, quinoline and the like are suitable. Pyridine is particularly preferred for convenience and economy in the formation of clothtreating agents as shown above.

The quaternary derivatives of the compounds of the invention are employed for treating woven or non-woven fibrous materials including wool, cotton, rayon, acetate, nylon and the like textiles, or paper, leather, wood, felt and similar organic fibrous constructions, and particularly cellulosic materials, by applying the selected quaternary derivatives, in aqueous medium buffered to about pH 6, to the cloth, removing any excess, drying at a temperature in the range of about 40 to 100 C., and heating the dried material to about 100 to 140 C. for a period of the order of about 5 to 30 minutes to fix the finish. Thereafter the material is desirably treated with a mildly alkaline washing to remove any residual acidic material, and dried. The treatment may be followed by a simple aqueous wash before drying, if desired, although this may be omitted since subsequent laundering of the treated fabric accomplishes the same purpose. The treatment may be termed a finishing treatment, since it is most usefully applied after weaving, forming, dyeing, weighting, filling or the like have been carried out. The cloth so treated appears to contain residual combined fluorine, indicating that at least a portion of the treating agent has reacted in some fashion, probably through the hydroxyl groups present in the fiber, although this theory is not to be construed as limiting the invention.

It is a surprising feature of cotton fabric treated with these quaternary derivatives that not only is the cloth rendered oil and water repellent but also it possesses a considerable degree of soil resistance, that is it does not become soiled as readily as untreated fabric. Furthermore, when soiled the fabrics thus treated are readily launderable to a clean state, after which they retain their oil and water repellency. The value of cloth so treated, for example, for childrens clothes, or for uniforms for workers around oily machinery, automotive service men and the like will be readily apparent.

The color of the fabrics treated with the compositions of the invention, and their tensile strength, are not af fected by the treatment. The hand of cotton fabrics appears to be improved by the treatment.

It is noted that the finishing treatment of the invention can be applied to resin-treated, wrinkle-resistant fabrics without adversely affecting the desirable non-wrinkling feature of such fabrics.

The compositions have furthermore been found to con fer oil and water-repellency on vitreous surfaces and the like, such as glass, including glass fibers.

The procedure for the preparation of the halomethyl ethers of the invention, their conversion to quaternary compounds, and the application of the latter to fabrics, especially cellulosic materials, are more specifically illustrated in the following examples, in which all parts are by weight and all percentages w./v. unless otherwise specified.

EXAMPLE 1 Anhydrous hydrogen chloride is passed through a solution of 155 parts of N-methyl-perfluorooctanesulfonamidohendecanol (prepared as described in Example 6 of US. Patent 2,803,656) in 320 parts of toluene containing 6.9 parts of paraformaldehyde, until no further absorption occurs and the reaction is complete. The solution is evaporated under reduced presure to remove toluene leaving the chloromethyl ether as a residue. N-methyl-ll-perfluorooctanesulfonamidohendecanoxymethyl chloride is a hard waxy solid which melts at about 50 C. The corresponding pyridinium salt is prepared therefrom by dissolving the above chloromethyl ether in about 300 parts of ether, adding 17.9 parts of pyridine and refluxing the solution for 1 hour. A precipitate of the quaternary salt forms and is collected, washed with ether and dried. N-rnethyl-l1-(perfiuorooctanesulfonamido)hendecanoxy 4 methyl pyridinium chloride thus prepared melts at about 93-108" C.

Analysis.-Calculated for C H F N O SCl: 3.45 percent N. Found: 3.47 percent N.

EXAMPLE 2 The process for production of soil-resistant, water and oil-repellent cloth using the quaternary derivatives of the compounds of this invention is carried out as follows:

The treating solution is prepared by warming sodium acetate trihydrate and the selected treating agent in water at the desired concentrations, which can range from about 0.1 to about 5 percent, at about 30 to 40 C. until solution is effected. It is to be noted that at higher concentration the solution tends to become mucilaginous and diffitficult to handle, resembling a colloidal dispersion. The cloth to be treated is soaked in the solution for 1 minute, removed and squeezed so that a weight of solution approximately equal to 75 to 125 percent of the weight of the cloth is retained. Under these conditions, the preferred concentration of treating solution ranges from about 0.5 to about 2 percent. The cloth is then dried for about 10 to 30 minutes at 40 to 100 C. and the treatment is fixed by heating the cloth for about 5 to 30 minutes at from about 100 to 140 C. The fixed, treated cloth is washed for about 30 minutes in an aqueous solution containing 0.1 percent w./v. of sodium lauryl sulfate and 0.2 percent w./v. sodium carbonate, at about 50 to 60 C., rinsed thoroughly and again dried. Other alkaline agents, such as dilute alkali metal hydroxides, bicarbonates, ammonium hydroxide and the like can be used instead of alkali metal carbonates.

The effectiveness of the treatments is determined by means of tests for spray rating, oil repellency rating and visual estimation of soil repellency both before further treatment and after one or more cycles of laundering.

For test purposes, laundering is accomplished by washing in a 1957 model automatic washing machine of the stationary tub type using a detergent under normal household procedures or by means of a standard 60 minute cycle in a Launder-O-Meter, using chip soap as specified in ASTM D-496.

Determination of water repellency rating is by means of the Spray Test (Standard Test Method No. 22-52, published in the 1952 Technical Manual and Yearbook of the American Association of Textile Chemists and Colorists, vol. XXVIII, p. 136).

Oil repellency of the treated cloth is measured by a severe test in which its resistance to penetration by solutions of mineral oil in heptane is determined. (Higher proportions of heptane bring about quicker penetration.) A material wet by mineral oil alone in less than 3 minutes rates zero, if it is only wet after 3 minutes it rates fifty, while resistance to penetration by a mixture of equal volumes of heptane and mineral oil rates 100. The ratings for resistance for 3 minutes are as follows.

Percent heptane: Rating 0 50 drying, it is subjected to tests to determine oil and water repellency with the following results:

Table I Cone. of treating solution Spray Oil Percent F rating repellency 1n fabric 1 Not determined.

Table II containing 1 percent of sodium acetate trihydrate by w./v. together with N-methyl-perfluorooctanesulfonamidohendecanoxymethyl pyridinium chloride in the concentrations indicated in Table III, and dried and cured under the conditions there set forth. After washing with a detergent (sodium lauryl sulfate), rinsing and drying, they are rated for oil and water repellency as well as dry soil resistance. Small portions of the fabric are removed and analyzed to determine the percentage of fluorine present.

Dry soil resistance simulates soil repellency of a material under especially exaggerated conditions. A control sample of untreated cloth and the treated sample to be tested are shaken together in a paper bag with about 2 ounces of a standard synthetic soil mixture having the composition described in the report of Salisbury et al., American Dyestuff Reporter, March 26, 1956, p. 199, then removed and sharply struck against a solid object to remove loosely adherent soil and compared visually with a similarly soiled untreated sample. The ratings are from to 3. These correspond to visual estimation to 0as dark as control (untreated cloth sample) 1slightly less dark than control Spray 2more than about half as dark as control repellency 25 3less than about half as dark as control Initial rating 80- 100+ While the ratings are subjective, and may vary to a cer- Aftef laundermg: 100+ tain extent as to the degree of soil involved, it is significant 80- igg+ that there is markedly less soiling of samples treated with 1 the compounds of the invention and this property is re- 70+ lgg 30 tained after laundering. Zgi 100 The conditions of treatment and results of tests after 100 the initial rinsing and drying and after 3 launderings using the Launder-O-Meter are set forth in the following table.

Table III Initial properties Properties after 3 launderings Specimen P tircint tDry LIDry tCure t( lrlxilree m ime, ernp. 1 I N0 P503 min. C. min. 011 Spray Dry soil Perl cent 011 Spray Dry S011 Perl cent 0. 5 40 15 120 90 a0 3 7 0.1 70 50 2 0.15 0. 5 40 30 120 20 90 80 3 0.17 70 50 2 0.13 0. 5 s0 120 90 3 0. 22 70 50 2 0.13 0. 5 50 30 120 10 90 30- 3 0. 24 70 50 1 0.12 1.0 50 22. 5 105 15 100 30+ 3 0. 38 100 70 a 0. 23 1. 0 40 30 120 10 100+ 80- 3 0. a (a) (a) 1. 5 40 15 90 10 100+ 80- 3 0. 39 90 2 0.16 1. 5 40 15 120 20 100+ 80 3 0. 42 100+ 2 0. 39 1. 5 40 30 90 20 100+ so 3 0. 54 100+ 70+ 1 0.30 1. 5 40 30 120 10 100+ 3 0. 57 100+ 70+ 3 0. 55 1. 5 00 15 20 90 3 0. 00 0 70 3 0.30 1. 5 00 15 10 100+ 30+ 3 2 0.12 100+ 70+ 3 0. 53 1. 5 00 30 90 10 100+ 90- a 0. 47 100 70+ 3 0. 24 1. 5 s0 30 120 20 100 30+ 5 7 0. 22 100+ 70+ 3 0.35 0.1 40 30 120 10 100- 70+ 3 1 0.12

1 Treating agent. 1 Values low due to inhomogenolty 0f analytncal samples. 3 Not determined.

The solution used for treating fabric as set forth above can also be applied to paper with slight modifications in procedure to avoid damaging the structure of the paper, which, as is well known, is weakened by treatment with water. Thus, the excess of treating solution is removed by permitting the paper to drip dry or by running the web between rolls, while drying and fixing are accomplished by heating the individual sheets or by hot-rollcalendering long strips or continuous rolls. The treated paper is oiland water-repellent.

EXAMPLE 3 This example further illustrates the effectiveness of the process of this invention and variations within the scope of the process. Samples of kier-boiled standard cotton EXAMPLE 4 N methyl 5 perfluorooctanesulfonamidopentanoxymethyl pyridinium chloride is prepared as follows, using the general procedure described above. A mixture of 198 parts of the dry sodium salt of N-methyl perfluorooctanesulfonamide and 61.5 parts of 5-chloropentyl acejeans cloth are treated as described above with solutions 75 tate is stirred at about 120 to C. for 15 hours and then cooled. The reaction mixture is extracted with successive portions of diethyl ether, the combined ethereal extracts evaporated and the residue distilled under re duced pressure. N-methyl-S-perfluorooctanesulfonamidopentyl acetate boils at about 140 C. to 145 C. under 0.4 mm. Hg pressure and melts at about 40 C.

To a solution of 131.3 parts of the acetate ester in about 100 parts of ethanol is slowly added a solution of 15 parts of sodium hydroxide in 40 parts of water. The resulting solution is stirred at about 60 to 70 C. for 15 hours, cooled, and diluted with an equal volume of water. The mixture is acidified with dilute hydrochloric acid and the crystalline -(N-methyl-perfiuorooctanesulfonarnido)pentanol is collected. After drying, it melts at about 735 to 75 C.

A mixture of 35 parts of the above N-methyl-S-perfluorooctanesulfonamidopentanol and 2 parts of paraformaldehyde in about 120 parts of toluene is treated with hydrogen chloride gas as described hereinabove until absorption ceases and the solution has become clear and homegeneous. The toluene is then removed under reduced pressure and the N-methyl-5-perfiuorooctanesulfonamidopentanoxymethyl chloride is obtained as a waxy residue.

The residue is taken up in 100 parts of diethyl ether and 7 parts of pyridine are added. After standing for about 16 hours, the crystalline ether-insoluble N-methyl- S-perfluorooctanesulfonamidopentanoxymethyl pyridinium chloride formed in the reaction has precipitated and is collected, Washed with ether and dried. It is obtained as hard waxy solid melting about l08l20 C.

Calculated for C H F SO N Cl' /2H O1 N=3.8l; H O=1.22. Found: C=32.6; N=3.8; H O: 1.8.

N methyl 5 perfluorooctanesulfonamidopentanoxymethyl pyridinium chloride is employed for treating kierboiled cotton jeans cloth as described above, using a 2 percent aqueous solution containing 1 percent of sodium acetate. The soaked cloth is dried for 30 minutes at 100 C. and then cured for 5 minutes at 135 C. The treated fabric has an oil rating of 100+ and a spray rating of 80; and contains 0.5 percent F. After laundering in the Launder-O-Meter, the oil rating is 100+, spray rating 70+ and there is still 0.48 percent F in the cloth. The dry soil rating both before and after laundering is +3, that is, visually estimated, the treated cloth is less than about one-half as readily soiled as an untreated sample of the cloth.

EXAMPLE 5 When N-ethyl-6 perfiuorooctanesulfonamidohexanol, N-methyl-4 perfluorobutanesulfonamidobutanol, N-perfiuorooctanesulfonamidoethanol and N-propyl-2 perfluorooctanesulfonamidoethanol are employed in the above procedures, except that anhydrous hydrogen bromide is used instead of hydrogen chloride, the corresponding bromomethyl ethers are formed as waxy solids, and are respectively, N-ethyl-6-perfluorooctanesulfonamidohexanoxymethyl bromide, N-methyl 4 perfluorobutanesulfonamidobutanoxymethyl bromide, N-perfiuorooctanesulfonamidoethanoxymethyl bromide and N-propyl-perfluorooctanesulfonamidoethanoxymethyl bromide. When these latter bromomethyl ethers are dissolved in anhydrous ether and the calculated stoichiometric amounts of triethylamine are added, using the procedure hereinabove set forth, the surface-active quaternary salts which precipitate are respectively (Nethyl-perfluorooctanesulfonamidohexyloxymethyl) triethylammonium bromide, (N- methyl perfiuorobutanesulfonamidobutoxymethyl)triethyl ammonium bromide, (N-perfluorooctanesulfonamidoethanoxy)triethyl ammonium bromide and (N-propylperfluorooctanesulfonamidoethoxymethyl) triethyl ammonium bromide.

Likewise, using the procedure described in Examples 1 and 4, but starting with N-butyl-8-perfluorododecanesulfonamidooctanol and N-hexyl-12-perfluorohexanesulfonamidododecanol, there are produced N-butyl-S-perfiuorododecanesulfonamidooctanoxymethyl chloride and N-hexyl-12-perfluorohexanesulfonamidododecanoxymethyl chloride, from which are prepared, using tri-n-hexylamine in ether solution, the corresponding N-butyl-8-perfluorododecanesulfonamidooctanoxymethyl tri n hexylammonium chloride and N-hexyl-IZ-perfiuorohexanesulfonamidododecanoxymethyl tri n heXyl-ammonium chloride.

These quaternary compounds are also useful for imparting waterand oil-repellent finishes to textiles as described herein.

What is claimed is:

1. A compound of the formula:

wherein R is perfluoroalkyl having 4 to 12 carbon atoms, R is alkylene having 1 to 12 carbon atoms, R is a member of the group consisting of hydrogen and alkyl having from 1 to 6 carbon atoms, and X is a halogen of the group consisting of chlorine and bromine.

2. A compound of the formula:

RI ntsoz-i i-n-cmocmo xwherein R is perfluoroalkyl having 4 to 12 carbon atoms, R is alkylene having 1 to 12 carbon atoms, R is a member of the group consisting of hydrogen and alkyl having from 1 to 6 carbon atoms, Q is a nitrogenous organic residue selected from the group consisting of trialkylamino having up to 36 carbon atoms, alkaryl amino having up to 8 carbon atoms, pyridino, picolino, lutidino and quinolino and X is a holgen of the group consisting of chlorine and bromine.

3. N methyl 11 perfluorooctanesulfonamidohendecanoxymethyl chloride.

4. N methyl 5 perfiuorooctanesulfonamidopentanoxymethyl chloride.

5. N methyl 11-perfluorooctanesulfonamidohendecanoxymethyl pyridinium chloride.

6. N methyl 5 perfiuorooctanesulfonamidopentanoxymethyl pyridinium chloride.

7. The process for the production of halomethyl ethers which comprises treating a compound of the formula:

wherein Rf is a perfluoroalkyl group containing 4 to 12 carbon atoms, R is an alkylene bridging radical containing 1 to 12 carbon atoms and R is a member of the group consisting of hydrogen and alkyl radicals having from 1 to 6 carbon atoms; with formaldehyde and a member of the group consisting of anhydrous hydrogen chloride and anhydrous hydrogen bromide while maintaining the temperature in the range of from about 25 to C.

8. A cellulosic fabric having oiland water-repellent properties, finished with N-methyl-ll-perfluorooctanesulfonamidohendecanoxymethyl pyridinium chloride.

9. A cellulosic fabric having oiland water-repellent properties, finished with N-rnethyl-S-perfiuorooctanesulfonamidopentanoxymethyl pyridinium chloride.

10. The process for rendering fibrous materials Waterand oil-repellent, which comprises treating the fibrous material with a quaternary amine salt of a compound of the formula:

wherein R; is perfluoroalkyl having 4 to 12 carbon atoms, R is alkylene having 1 to 12 carbon atoms, R is a member of the group consisting of hydrogen and alkyl having from 1 to 6 carbon atoms, and X is a halogen of the group consisting of chlorine and bromine, in aqueous medium buffered to about pH 5.5 to 6.5, drying the treated fibrous material and heating the dried, treated material to about 9 100 to 140 C. for a period of the order of 5 to 30 minutes.

11. A fabric finished with a quaternary amine salt of a compound of the formula:

Bi Rr-S 0zN-ROH,O omx wherein R, is perfluoroalkyl having 4 to 12 carbon atoms, R is alkylene having 1 to 12 carbon atoms, R is a member of the group consisting of hydrogen and alkyl having from 1 to 6 carbon atoms, and X is a halogen of the group consisting of chlorine and bromine; whereby the fabric contains residual combined fluorine and has oiland water-repellent properties.

References Cited in the file of this patent UNITED STATES PATENTS Baldwin et al. Feb. 7, 1939 Bock June 18, 1940 Wirth et a1. Aug. 27, 1940 Hurd Mar. 16, 1943 Diesslien et al. Sept. 4, 1951 Couper Sept. 2, 1952 Brice et a1. Jan. 24, 1956 Brown Aug. 14, 1956 Musser May 28, 1957 Ahlbrecht Aug. 20, 1957 

1. A COMPOUND OF THE FORMULA:
 10. THE PROCESS FOR RENDERING FIBROUS MATERIALS WATERAND OIL-REPELLENT, WHICH COMPRISES TREATING THE FIBROUS MATERIAL WITH A QUATERNARY AMINE SALT OF A COMPOUND OF THE FORMULA: 